Systems Analysis and Integration
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w1c2.pptCIS320
Systems Analysis and Integration
Week 1
System Requirements
Information Gathering Technique
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Systems Analysis and Design in a Changing World, 6th Edition
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Chapter 2
- Overview
- This chapter focuses on Core Process 3 (Systems analysis activities, tools and techniques) to discover and understand the details of the problem or need
- Outline
- Systems Analysis Activities
- What Are Requirements?
- Models and Modeling
- Stakeholders
- Information-Gathering Techniques
- Documenting Workflows with Activity Diagrams
Systems Analysis and Design in a Changing World, 6th Edition
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Systems Analysis and Design in a Changing World, 6th Edition
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Systems Analysis Activities
Involve discovery and understanding
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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Systems Analysis Activities
- Gather Detailed Information
- Interviews, questionnaires, documents, observing business processes, researching vendors, comments and suggestions
- Define Requirements
- Modeling functional requirements and non-functional requirements
- Prioritize Requirements
- Essential, important, vs. nice to have
- Develop User-Interface Dialogs
- Flow of interaction between user and system
- Evaluate Requirements with Users
- User involvement, feedback, adapt to changes
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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What Are Requirements?
- System Requirements =
- Functional requirements
- Non-functional requirements
- Functional Requirements– the activities the system must perform
- Business uses, functions the users carry out
- Non-Functional Requirements– other system characteristics
- Constraints and performance goals
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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FURPS+ Requirements Acronym
Systems Analysis and Design in a Changing World, 6th Edition
Which requirements are these?
Reliability
Design Constraints
Performance
Functional
Security
Usability
The user must be able to add items to the shopping cart, check out and place order.
User should need no more than 5 clicks to complete an order.
Average response time should be less than 300 ms. Maximal response time is no longer than 2 seconds.
The website requires Javascript to be turned on.
The website should achieve at least 99.99 uptime.
Users must use HTTPS for checkout
_______ requirements describe…
Design Constraint
Functional
Performance
Security
Reliability
Usability
the activities that the system must perform
operational characteristics related to users, such as the user interface, related work procedures, on-line help and documentation
operational characteristics related to measures of workload, such as throughput and response time
operational characteristics related to the environment, hardware, and software
the dependability of a system, that is, how often it exhibits behaviors such as service outages and incorrect processing
which users can perform what system functions under what conditions
Systems Analysis and Design in a Changing World, 6th Edition
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Models and Modeling
- How do we define requirements?
- After collecting information, create models
- Model– a representation of some aspect of the system being built
- Types of Models
- Textual model– something written down, described
- Graphical models– diagram, schematic
- Mathematical models– formulas, statistics, algorithms
- Unified Modeling Language (UML)
- Standard graphical modeling symbols/terminology used for information systems
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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Information Gathering Techniques
Interviewing users and other stakeholders
Distributing and collecting questionnaires
Reviewing inputs, outputs, and documentation
Observing and documenting business procedures
Researching vendor solutions
Collecting active user comments and suggestions
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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1. Interviewing Users and Other Stakeholders
- Prepare detailed questions
- Meet with individuals or groups of users
- Obtain and discuss answers to the questions
- Document the answers
- Follow up as needed in future meetings or interviews
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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2. Distribute and Collect Questionnaires
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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3. Review Inputs, Outputs, and Procedures
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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Additional Techniques
4. Observe and Document Business Processes
- Watch and learn
- Document with Activity diagram (next section)
5. Research Vendor Solutions
- See what others have done for similar situations
- White papers, vendor literature, competitors
6. Collect Active User Comments and Suggestions
- Feedback on models and tests
- Users know it when the see it
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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Documenting Workflows/Business Processes with Activity Diagrams
- Workflow– sequence of processing steps that completely handles one business transaction or customer request
- Activity Diagram– describes user (or system) activities, the person who does each activity, and the sequential flow of these activities
- Useful for showing a graphical model of a workflow
- A UML diagram
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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Activity Diagrams Symbols
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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Activity Diagram for RMO Order Fulfillment
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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Summary
- Systems analysis activates correspond to the core SDLC process Discover and understand details
- Systems analysis involves defining system requirements– functional and non-functional
- Analysis activities include
- Gather detailed information
- Define requirements
- Prioritize requirements
- Develop user-interface dialogs
- Evaluate requirements with users
- FURPS+ is the acronym for functional, usability, reliability, performance, and security requirements
Systems Analysis and Design in a Changing World, 6th Edition
Systems Analysis and Design in a Changing World, 6th Edition
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Summary
- Models and modeling are used to explore and document requirements
- A model represents some aspect of a system, and can include textual, graphical, and mathematical models
- Unified Modeling Language (UML) is the standard set of notations and terminology for information systems models
- Information gathering techniques are used to collect information about the project
- Interviews, questionnaires, reviewing documents, observing business processes, researching vendors, comments and suggestions
- The UML Activity Diagram is used to document (model) workflows/business processes after collecting information
Systems Analysis and Design in a Changing World, 6th Edition
